Brewing apparatus with a drainage valve

Abstract

The invention relates to a brewing apparatus, in particular for coffee, comprising a drainage valve, which is located on the one hand in a brewing liquid path between a brewing liquid container and a brewing unit of the brewing apparatus and on the other hand, in a drainage liquid path between the brewing unit and an outlet of the brewing apparatus. In a brewing position of the drainage valve, the brewing liquid path is released and the drainage liquid path is blocked. The brewing apparatus is characterised by a drainage position of the drainage valve in which both the drainage liquid path and also the brewing liquid path are released and a decalcification position of the drainage valve in which the brewing liquid path is blocked and a decalcification liquid path is produced between the brewing liquid container and the outlet via the drainage valve.

That which is claimed: 
     
       1. A brewing apparatus for producing coffee beverages, comprising
 a liquid container for a brewing liquid or a decalcification liquid, 
 a brewing unit including a brewing chamber being configured for brewing coffee, 
 an outlet, 
 a drainage valve being configured to be brought into three different positions, wherein the three different positions include a brewing position, a drainage position and a decalcification position, wherein the drainage valve is arranged with respect to the liquid container, the brewing unit and the outlet so that, 
 when the drainage valve is in the brewing position a brewing liquid path is provided between the liquid container and the brewing chamber via the drainage valve enabling an amount of the brewing liquid to flow via the drainage valve into the brewing chamber for brewing coffee with the brewing liquid in the brewing chamber, and, 
 when the drainage valve is in the drainage position a drainage liquid path is provided between the brewing unit and the outlet via the drainage valve enabling a drainage luquid coming from the brewing chamber to flow via the drainage valve to the outlet, and, 
 when the drainage valve is in the decalcification position a decalcification liquid path is provided between the liquid container and the outlet via the drainage valve enabling an amount of the decalcification liquid to flow from the liquid container via the drainage valve to the outlet, and 
 wherein the drainage valve is configured to block the drainage liquid path when the drainage valve is in the brewing position and to block the brewing liquid path when the drainage valve is in the decalcification position. 
 
     
     
       2. The brewing apparatus according to  claim 1 , wherein the drainage valve comprises a cylindrical sleeve with an inlet for the brewing liquid coming from the liquid container and an outlet for the drainage liquid coming from the brewing unit, which are placed in a manner offset with respect to one another on their circumference such that in a horizontal mounting position of the sleeve, its inlet is located at a higher position than its outlet. 
     
     
       3. The brewing apparatus according to  claim 1 , wherein the drainage valve has an outlet for the brewing liquid flowing to the brewing unit and an inlet for the drainage liquid coming from the brewing unit, and this outlet and this inlet are designed as a common brewing and drainage connection. 
     
     
       4. The brewing apparatus according to  claim 1 , wherein the drainage valve has a sleeve, two sealing collars disposed in the sleeve and a waisted piston which is guided centrally in the sleeve, each of the two sealing collars having a through opening, the waisted piston having a waist section and being configured to be brought into a position in which the waist section of the piston passes through each through opening of each of the two sealing collars without touching the two sealing collars, the two sealing collars being disposed successively in the sleeve so that the two sealing collars divide three sealing spaces each adjoining at least one of the sealing collars, each through opening providing a continuous fluid connection between two of the three sealing spaces. 
     
     
       5. The brewing apparatus according to  claim 4 , wherein the piston has respectively one flange section at each of the two ends of the waist section and is configured to be brought into one of the brewing position and the decalcification position as desired in which respectively one of the flange sections abuts sealingly against one of the two sealing collars and the waist section passes through the through opening of the other one of the two sealing collars so that in each case two of the sealing spaces are in communication with each other and are sealed with respect to the respectively third sealing space. 
     
     
       6. The brewing apparatus according to  claim 5 , wherein an inlet for the brewing liquid coming from the liquid container is formed in the sealing space of the drainage valve which lies between the two sealing collars disposed in the sleeve. 
     
     
       7. The brewing apparatus according to  claim 6 , wherein the outlet for the brewing liquid flowing to the brewing unit, the inlet for the brewing liquid coming from the liquid container and the outlet for the drainage liquid flowing from the drainage valve open into respectively different sealing spaces. 
     
     
       8. The brewing apparatus according to  claim 4 , wherein a linear stepping motor is provided for adjusting the piston in the drainage valve. 
     
     
       9. The brewing apparatus according to  claim 2 , wherein the drainage valve has an outlet for the brewing liquid flowing to the brewing unit and an inlet for the drainage liquid coming from the brewing unit, and this outlet and this inlet are designed as a common brewing and drainage connection. 
     
     
       10. The brewing apparatus according to  claim 2 , wherein the drainage valve has a sleeve, two sealing collars disposed in the sleeve and a waisted piston which is guided centrally in the sleeve, each of the two sealing collars having a through opening, the waisted piston having a waist section and being configured to be brought into a position in which the waist section of the piston passes through each through opening of each of the two sealing collars without touching the two sealing collars, the two sealing collars being disposed successively in the sleeve so that the two sealing collars divide three sealing spaces each adjoining at least one of the sealing collars, each through opening providing a continuous fluid connection between two of the three sealing spaces. 
     
     
       11. The brewing apparatus according to  claim 10 , wherein the piston has respectively one flange section at each of the two ends of the waist section and is configured to be brought into one of the brewing position and the decalcification position as desired in which respectively one of the flange sections abuts sealingly against one of the two sealing collars and the waist section passes through the through opening of the other one of the two sealing collars so that in each case two of the sealing spaces are in communication with each other and are sealed with respect to the respectively third sealing space. 
     
     
       12. The brewing apparatus according to  claim 11 , wherein an inlet for the brewing liquid coming from the liquid container is formed in the sealing space of the drainage valve which lies between the two sealing collars disposed in the sleeve. 
     
     
       13. The brewing apparatus according to  claim 12 , wherein the outlet for the liquid flowing to the brewing unit, the inlet for the brewing liquid coming from the brewing liquid container and the outlet for the drainage liquid flowing from the drainage valve open into respectively different sealing spaces. 
     
     
       14. The brewing apparatus according to  claim 10 , wherein a linear stepping motor is provided for adjusting the piston in the drainage valve. 
     
     
       15. The brewing apparatus according to  claim 3 , wherein the drainage valve has a sleeve, two sealing collars disposed in the sleeve and a waisted piston which is guided centrally in the sleeve, each of the two sealing collars having a through opening, the waisted piston having a waist section and being configured to be brought into a position in which the waist section of the piston passes through each through opening of each of the two sealing collars without touching the two sealing collars, the two sealing collars being disposed successively in the sleeve so that the two sealing collars divide three sealing spaces each adjoining at least one of the sealing collars, each through opening providing a continuous fluid connection between two of the three sealing spaces. 
     
     
       16. The brewing apparatus according to  claim 15 , wherein the piston has respectively one flange section at each of the two ends of the waist section and is configured to be brought into one of the brewing position and the decalcification position as desired in which respectively one of the flange sections abuts sealingly against one of the two sealing collars and the waist section passes through the through opening of the other one of the two sealing collars so that in each case two of the sealing spaces are in communication with each other and are sealed with respect to the respectively third sealing space. 
     
     
       17. The brewing apparatus according to  claim 16 , wherein an inlet for the brewing liquid coming from the liquid container is formed in the sealing space of the drainage valve which lies between the two sealing collars disposed in the sleeve. 
     
     
       18. The brewing apparatus according to  claim 17 , wherein the outlet for the brewing liquid flowing to the brewing unit, the inlet for the brewing liquid coming from the liquid container and the outlet for the drainage liquid flowing from the drainage valve open into respectively different sealing spaces. 
     
     
       19. The brewing apparatus according to  claim 15 , wherein a linear stepping motor is provided for adjusting the piston in the drainage valve. 
     
     
       20. The brewing apparatus according to  claim 7 , wherein a linear stepping motor is provided for adjusting the piston in the drainage valve.